As is well known, a mechanical pencil has a problem that a drawn line becomes bold, since a writing lead may locally abrade as the writing proceeds.
Then, the present applicant has previously proposed a mechanical pencil provided with a rotational drive mechanism in which the writing lead is gradually rotated in one direction using writing pressure applied to the writing lead. This is disclosed in Patent Documents 1 and 2 etc.
According to this mechanical pencil, in the case where a body cylinder is inclined to a writing side (page) at around 40 to 80 degrees (for example), every time a stroke is drawn, the writing lead is slightly rotationally driven in one direction, so that a tip portion of the writing lead is always kept sharp in the shape of a cone. Thus, it is possible to write down and always give substantially the same line width.